Ok, ok, I know that almost every engine service manual in the world shows a cylinder ridge reamer being used on a cylinder before taking the piston and connecting rod out. So why on earth would I tell you not to use one ? Better yet, if you have one, throw it away or sell it at a yard sale !
First of all in the 25 years I have owned an Automotive Machine Shop, I have NEVER seen an engine that required a ridge reamer to be used so that the pistons would come out of the block. Never, period.
I have however seen a few engine blocks that have been pretty much ruined by the use of this tool.
The first thing you have to understand is if an engine block has that much wear on it that it has a ridge at the top of the piston ring travel, it needs to be bored to the next oversize . . . period. If you can feel the ridge with your fingernail, the cylinder is probably at least 10 thousanths oversize at that point. I have seen wear ridges on late model Chevy engines that were almost 30 thousanths ( .030" )
So, you have a cylinder that is almost .030" worn already, then you take the good old ridge reamer and cut the ridge out of the block . . . . now it probably .040" oversize where you cut the ridge out !!!! So you started out with a block that could have been bored .030 and now you have one that will probably have to go at least .040", maybe even .060" All because of that nifty old tool. If this is an older engine with limited oversize pistons available, you may have turned your block into scrap metal.
The instructions don't tell you any of this stuff !
So as nice as it looks, take my advice and leave it in your tool box and just take the engine apart without it. Your engine block will thank you.